The estimation of unwanted fertility is a major objective of demographic surveys, including DHS surveys conducted in Asia, Africa, and Latin America. Levels and trends in unwanted fertility are important input to the formulation of population policy and the evaluation of family planning program performance. Unwanted fertility is posited to have multiple consequences at levels ranging from the societal down to the pregnancy/child, although the nature and magnitude of such consequences remains an active topic of research. Yet existing methods for estimating unwanted fertility are known to be defective, among other reasons because they rely on attitudinal data whose validity and reliability are suspect. The proposed research will develop and apply a new estimator of unwanted fertility - the "two-survey estimator", so-named because in its basic form it draws on data from two successive cross-sectional surveys. This estimator relies on the fertility attitude regarded by most scholars as most trustworthy, namely the stated preference for another child at the time of the survey. Under reasonable assumptions, the two-survey estimator should produce less biased estimates of unwanted fertility than the most widely used existing methods. The new estimator has the limitation of producing only aggregate-level estimates, but such estimates are the primary datum for policy formulation and program evaluation. In the first phase of this project, a basic version of the two-survey estimator will be implemented. Subsequently, extensions of the basic estimator will be developed that will make it applicable to a diverse range of data circumstances (including, its name notwithstanding, a one-survey version of the two-survey estimator) and that will yield output that is either more accessible to a broad audience (unwanted TFRs) or more acceptable to a technical audience (confidence intervals for the two-survey estimates). In the final phase of the project, the new estimator will be applied to the full body of DHS data (a maximum of 200 surveys), generating revised estimates of unwanted fertility for 42 countries (or, if the one-survey version functions as expected, estimates for as many as 70 countries). Output from the project will include: a paper presenting the methodology; revised estimates of unwanted fertility for a large number of countries and historical periods, posted on the Web and analyzed in a second paper; and, finally, software in the public domain that implements the method. [unreadable] [unreadable]